Underwater breathing apparatus



O. D. YARBROUGH' UNDERWATER BREATHING APPARATUS Sept. 27, 1949.

4 Sheets-Sheet 1 Filed Oct. 31, 1946 INVENTOR. M O

9 arroklvxx' Sept. 27, 1949. v o. D. YARBROUGH UNDERWATER BREATHING APPARATUS Filed 001;. 31, 1946 4 Sheets-Sheet 2 INVENTOR. 6%.. 6.

BY r

Sept. 27, 1949. o. D. YARBROUGH 2,483,116

UNDERWATER BREATHING APPARATUS Filed Oct; 51, 1946 Y 4 Sheets-Sheet'4 2 INVENTOR.

Patented Sept. 27, 1949 UNITED (S TATES TENT QFMQ UNDERWATER BREATHJNGAPPARATUS Oscar D. Yarbrough, Washington, D. "0. Application October 31, 1946, Serial No. 701016 This invention relates to improvements in self- .contained breathing apparatus, and more particularly in breathing apparatus adapted .for use in under-water .swimming, diving and salvage work.

'To date, self-contained breathing apparatus, particularly those designed for underwater use, have had high resistance to breathing by the wearer. The principal disadvantage of high breathing resistance is that it requires the expenditure of additional energy by the wearer of the apparatus so that .he rapidly becomes fa- .tigued.

Another disadvantage round in self-contained breathing apparatus used under water is that no means are provided for the wearer to control his buoyancy. In order to submerge, the wearer must be provided with weights to .overcome his natural buoyancy and the buoyancy of the apparatus breathing bag. In order to ascend, the wearer must either discard his weights underwater or be pulled to the surface by a life line. The use of a life line requires additional person- .nel to 'be stationed on the surface of the water to pull up the diver when necessary. Discarding weights is not desirable since it requires time,

particularly if the wearer desires to surface rapidly.

In some cases persons operating underwater are subject to shock from pressure waves transmitted through the water from the detonation of depth changes, from underwater blasting, or from other explosives. Heretofore, no means have been provided to protect the wearer of a selfcontained breathing apparatus from injuries caused by these explosive forces. Such blast injuries are particularly dangerous in the abdominal regions of the wearer.

It is an object of my invention to provide a self-contained breathing apparatus so constructed that the wearer can breathe with ease by keeping the resistance to breathin in the apparatus to a minimum.

It is a further object of this invention to provide an apparatus whose buoyancy can be controlled so that the wearer may move about underwater, ascend, and descend without having to remove the weights that are necessary to overcome his natural buoyancy and the residual buoyancy of the apparatus due to the air contained in the breathing bag.

Another object of my invention is to provide means for protecting the wearer from injuries that might be caused by underwater explosions.

Still another object of my invention is to provide means for keeping the apparatus wearer '2 afloat on the surface of the water should he come to the surface at apoint where there is no boat or other .means of flotation and should his supply o'f respirable air for underwater breathing be exhausted.

Generally, I achieve these objects in my invention by providing an apparatus in which the breathing bag is divided into two sections, one section from which the wearer inhales and the other section into which he exhales. An air purifying canister is placed between the exhalation and inhalation sections so that all exhaled air must pass through the canister. There are no tubing connections within the breathing bag to the canister, and the canister is so constructed that a large filtering area is exposed to the gas flow. In this manner, any restrictions in the line of gas flow are eliminated so that breathing resistance is kept to a minimum. By providing a breathing bag so shaped that it is draped over both the chest and back of the wearer with a substantial portion positioned over the wearers shoulders and so divided that each section lies over one shoulder of the wearer andthe corresponding portion of his chest and back, any resistance to breathing caused by forces due to water pressure is kept, to a minimum. Generally, the wearer is in either vertical, horizontal, or oblique position underwater. Rarely does he have to assume a sideways position. By dividing the bag in the above described fashion, equal pressure efiects are exerted by the water on both the inhalation and exhalation sections So that no pressure difierential causing increased breathing effort to move the air from the exhalation section to the inhalation section and then to the mask and the wearers respiratory system is encountered.

In conjunction with the breathing bag and air purifying canister, I have provided a supply of compressed oxygen carried in a cylinder, a facepiece, breathing tubes, and directional flow check valves to form a complete breathing circuit.

1 have provided a buoyancy vest that is an integral part of the apparatus but which is separated from the breathing bag so that the buoyancy volume is contained in an entirely separate reservoir. By enabling gas from the compressed oxygen cylinder containing oxygen for breathing to flow into the vest, the wearer can control his buoyancy without having to remove the weights necessary to keep him underwater. The amount of oxygen used for this purpose is so small that it does not significantly decrease the operating life of the apparatus.

so that water does not enter the breathing bag and air purifying canister. Should his supply, of compressed gas be exhausted, a small carbon dioxide cartridge is provided toinflate the buoyancy vest, thus enabling the wearer toremain afloat.

In one embodiment of my invention, a carbon dioxide cartridge is also used to provide sufiicient buoyancy to bring the wearer to the surface of the water.

The construction and operation of my invention can be seen more clearly by referring to the drawings, in which:

Fig. 1 is a front view of the apparatus showing it being worn by a diver;

Fig. 2 is a rear view of the apparatus as worn;

Fig. 3 is a top view of the apparatus less the facepiece as it would appear if laid out on a flat surface. Part of the breathing bag is broken away to show more clearly the construction of the buoyancy vest;

Fig. 4 is a section view taken along line IVIV of Fig. 3;

Fig. 5 is a section view taken along line VV of Fig. 3;

Fig. 6 is a section view taken along line VI-VI of Fig. 3; and

Fig. '7 is a broken view showing another embodiment of the control valve in relation to the apparatus.

Referring to the drawings, the apparatus consists of a tight fitting, fiexible molded facepiece l which is held securely in place on the wearers face by flexible rubber headstraps 2. The facepiece is provided with a single, fiat, glass lens 3 extending laterally in the iacepiece so as to cover both eyes of the wearer. At the sides of the iacepiece are mounted the inhalation check valve 4 and the exhalation check valve 5. A flexible rubber breathing tube 6 is attached to breathing bag I by coupling nut '8. A manually operated plunger valve 9, normally open, is attached to the exhalation check valve 5 so that the gas passage in the exhalation circuit may be closed. A flexible rubber breathing .tu'be H, attached to the manually operated plunger valve, is connected to the breathing bag 1 by a coupling nut at I.

'A manually operated plunger valve I 2 is located in the lower portion of the facepiece. This valve is normally closed unless the wearer depresses the plunger l3.

The main portion of the apparatus consists of the breathing bag 1, the buoyancy vest M, the oxygen cylinder 15, and the carbon dioxide absorbent canister 15. The breathing bag 1 is constructed of a lightweight, durable, rubberized fabric. It is divided into two sections, the inhalation side I! and the exhalation side 18. This division is made in the front by cementing the two sides of the bag together to form seam [9 which is shown as a shaded area in Fig. 1. The back of the breathing bag 1 is split into an open section on either side to receive the canister I 6. The bag at this split is provided with soft, pliable,

rubber sections. One side is slightly larger than the other so that one rubber section 2! overlaps the other 22, which is in Contact with the canister 18. A metal clamp 23 is placed over the outer rubber section 2| and tightened so as to apply a uniform circumferential compression to seal rubber portion 2| against rubber portion 22, and rubber portion 22 against the canister 16. On :both sides of the breathing bag I, a rubber reinforcing strip 24 covering the entire inside of each half of the breathing bag extends the length of the canister 16 to protect the rubberized fabric ofgthe bag from abrasion due to repeated inserbreathing bag I for attachment of the threaded coupling nuts 8 on the facepiece breathing tubes. These inserts extend as elbows into the interior of the breathing bag to prevent the bag from collapsing and closing oil? the breathing circuit.

0n the wearer, the breathing bag is so positioned that the portion containing the carbon dioxide absorbent canister It falls high on the :back of the wearer. The carbon dioxide canister I6 is an ovalshaped canister constructed Of sheet metal. The interior is filled with a chemical 10 which is a, combination of lime, sodium hydroxide, Portland cement, kieselguhr, and water, and which is la highly eflicient carbon dioxide absorbent. The

canister is so constructed that it has a large cross sectional area in proportion to its length, thus reducing resistance to gas fiow. The outlets in breathing bag 1 containing threaded inserts 251818 so positioned that they are located over the wearers shoulders so that they are approximately at the highest point of breathing bag 1 when the apparatus is worn.

In the front, breathing bag 7 terminates at seam 26 at, which point the two sides of the bag are joined together in a gas tight and leak-proof seam. The rubberized fabric material, however, .is extended to form a pocket 21 which holds oxygen cylinder I5. Constructed of forged alloy steel so that it will safely hold gas at 2000 p. s. i., oxygen cylinder I5 is provided with a high pressure opening and closing valve 29 of conventional design. Attached to cylinder valve 29 and extending downwardly is control valve 30. Valve 30 is a high pressure needle valve consisting of a brass body and a handwheel 32 attached to a stainless steel stem (not shown) that passes through a packing and terminates in a V-shaped :point. I A flexible rubber tube 33 is connected to control valve 30 and extends upwardly into the inhalation side ll of breathing bag 1. Tube 33 is enclosed by a sheath 34 of the rubberized bag material over a portion of its length to hold it close to the wearers body so that it cannot become fouled by underwater obstructions. A strap H constructed of strong webbing fits around the neck portion of cylinder valve 29 to prevent oxygen cylinder l5 from slipping out of pocket 21. Pocket 21 terminates in a seam I2 at its lower side. D ring 13 is attached to seam 12 at its center portion by a rubberized fabric tab 35 that is doubled over the D ring and cemented Ito the seam.

Extending downwardly in front of the wearer, so as to enclose his abdominal region, is buoyan y vest l 4. Vest I4 is constructed of the same lightweight, durable rubberized fabric as breathin bag 1. It is attached to breathing bag I at points 31 and 38 so that the apparatus consists of a single lightweight garment. The pocket 21 containing cylinder [5 fits over the upper portion of vest 14 when the apparatus is worn. The buoyancy vest 14 is divided into two sections ".39 and .48 with tubular member 4| which maybe constructed of rubber or metal interconnecting the two sections to permit gas flow between them. Otherwise, sections 39 and :49 are separated by seam 42 formed by joining the two sides of the vest together. The division of the vest [-4 into two sections tends to flare the vest'out toward the sides when inflated so that the point of greatest expansion when inflated is not at the center of the vest.

Section 39 has a carbon dioxide inflator valve '43 of conventional design attached in its lower portion. At the top of section 39 is a screw type outlet valve 44. Valve 45, a screw type valve, is located in the lower portion of section 40. Valve '45 may be used either as an inlet or outlet valve. In the upper portion of section 40 is located valve 46, a screw type valve, to which rubber tube 47 is attached. Valve 49 and tube 4'! are used to orally inflate buoyancy vest 94. At the side of section 39 of buoyancy vest 36 is buckle 48. Buckle 4B is attached to tab 49 by a leather strip 50 and rivets 5!. At approximately the same location on theside of section 40, D ring 52 is held in place by tab 53 which passes through the ring and is connected to the vest at point 54 in the same manner as O ring 13 is attached. D rings :55 are similarly attached at the bottom of seam 42 on buoyancy vest i4.

In'the rear of the breathing bag I at the section where canister i6 is located, D-rings 56 and 51 .are similarly attached. Belt 58 containing lead weights passes around the wearers waist and is attached to the apparatus at buckle 48 and D ring 52. Crotch strap 59 constructed of high tensile strength webbing is attached to the apparatus at D rings 55 and 5? by snaps 60 and 61. In the front of the apparatus, crotch strap 59 passes through D rings 55, up through D ring 13 and is then looped through D rings 55.

In one embodiment of my apparatus, as shown in Fig. '7, control valve 30 is replaced by valve t3. Valve 63 consists of a fitting '64 that connects to the outlet of oxygen cylinder valve 29, and a brass manifold section 95 into one side of which fitting 64 is threaded. In the other side of manifold .65 are threaded two control valves 66 and 6'! similar in construction to control valve 30. Rubber tube 69 corresponding to rubber tube 33 is connected to valve 91 and extends upwardly into the inhalation side ll of breathing bag 1. A flexible rubber tube 69 is attached to valve 66. Tube 69 extends down and is connected to valve 45 on buoyancy vest M. In this manner, buoyancy vest l4 may be inflated by the gas contained in oxygen cylinder l5.

In underwater operation, the apparatus is worn as shown in Figs. 1 and 2. The oxygen cylinder is filled initially with oxygenat a pressure of 2000 .p. s. i. Cylinder valve 29 is opened. Oxygen flows into the inhalation side ll of breathing bag I, through control valve 30 and rubber tube 33. The wearer may open and close control valve 30 to provide a supply of oxygen adequate for his respiratory requirements. From the inhalation side I! of breathing bag I, the oxygen flows to the facepiece i through breathing tube 6 and inhalation check valve 4. The oxygen then .fiow into the wearers lungs upon inhalation. Upon exhalation, the exhaled air containing carbon dioxide passes through the exhalation check valve 5, breathing tube l I and into the exhalation side 18 of breathing bag I. Inhalation check valve 4 .air will pass back through th inhalation breathing tube 6 and into the inhalation side of breathing bag 1. Upon inhalation again, the exhaled air is pulled through canister 19, containing a carbon dioxide absorbent chemical, where the carbon dioxide is removed. The purified air then passes into the inhalation side ll of breathing bag I and thence into the facepiece l and the wearers lungs. Control valve 30 is opened only to supply additional oxygen as the supply in the breathing bag becomes depleted due to consumption by the wearer. Exhalation check valve 5 closes on inhalation so that air is inhaled only 1 from the inhalation side I? of the breathing bag.

In this manner, a one-way circuit is provided in the apparatus so that all exhaled air must pass through canister 56 for removal of carbon dioxide.

Plunger valve l2 on facepiece I is used to initially purge the apparatus of nitrogen and to relieve any excess pressure that might be built up by permitting too great a flow of oxygen through control valve 39.

To control buoyancy underwater, a double control valve 53 may be attached to cylinder valve 29 as shown in Fig. 7. Valve '51 of the double valve controls the oxygen supply to the breathing ba 1 while the valve 65 is used to supply gas to the buoyancy vest l4. Should it be desired to release gas from the vest underwater, valves 44 and 40 at the top of the vest may be opened. The water pressure will then force out the gas.

Should the wearer desire to ascend without any attempt to control buoyancy, the carbon dioxide inflator valve dit is opened to permit gaseous carbon dioxide to fill buoyancy vest and provide sufficient buoyancy to bring the wearer to the surface and enable him to remain afloat there.

Should the wearer come to the surface at a point where he must remain afloat for some time before he is reached by a boat, he may close valve 9 and remove facepiece i. Valve 9 will close breathing tube 5 i so that water will not enter the exhalation side IQ of breathing bag 1 and damage the carbon dioxide absorbent material 10 in canister iii. Should his facepiece drag in the water, inhalation check valve 4 will automatically close in the water so that water cannot enter breatl ing tube 5 and the inhalation side it of breathing bag 7.

Where protection from blast injuries is desired, buoyancy vest M can be initially filled with a compressible gas either through valve 56, the carbon dioxide inflator valve 43, or by oral inflation through valve 45 and tube 4?. Additional weights must be provided to overcome this additional buoyancy. Buoyancy control can still be provided by supplying additional gas through valve -69. By filling the vest it intially with a compressible gas, a protective cushion is provided which can absorb the pressure waves set up by explosions in the water.

After the apparatus has been used, it may be necessary to remove canister i9 and replace it with a fresh one. Clamp 23 is removed and the breathing bag 7 is pulled apart by exerting force in opposite directions on either side of the bag so that bag is pulled open, permitting canister it to be removed.

According to the provisions of the patent statutes, I have explained the principle of my invention and have described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

I claim:

1. In a self-contained breathing apparatus of the character described, a breathing bag divided by a central seam extending lengthwise thereof into inhalation and exhalation portions, the bag being provided at one end of the seam with a passage connecting said portions, and an air purifying canister mounted in said passage so that all exhaled air passes through said canister before inhalation.

2. In a self-contained breathing apparatus of the character described, a breathing bag adapted to fit around the neck of a wearer and to fit over his shoulders with sections falling over his chest and back, said bag being divided into two separate sections, one for inhalation and one for exhalation, and a removable air purifying canister in a d bag between the inhalation and exhalation sections thereof.

3. In a self-contained breathing apparatus of the character described, an oblong breathing bag having an opening in its central portion for the wearers head, the rear portion of said bag being split so as to form two overlapping sections adapted to hold an air purifying canister Within the bag, and said bag being divided in the front by a seam and in the rear by said canister into two separate sections, one for inhalation and one for exhalation.

4. A self-contained breathing apparatus comprising a facepiece, inhalation and exhalation check valves connected to said facepiece, flexible breathing tubes, a breathing bag divided into inhalation and exhalation sections, a carbon dioxide absorbent canister interposed between said sections, a cylinder containing compressed oxygen, and a control valve to regulate the flow of oxygen into said breathing bag.

5. A self-contained breathing apparatus comprising a facepiece, inhalation and exhalation check valves connected to said facepiece, a manually operated valve located in the lower front portion of said facepiece, a breathing bag, breathing tubes connecting said facepiece to said bag,

said bag being divided into two separate sections, one for inhalation and one for exhalation, a removable canister containing a carbon dioxide absorbing chemical interposed between said bag sections so that all exhaled air passes through said canister, a clamp passing around the breathing bag enclosing said canister so as to seal the bag against the canister, a cylinder containing compressed oxygen, a control valve to regulate the flow of oxygen into said breathing bag, and a buoyancy vest attached to said breathing bag.

6. A self-contained breathing apparatus comprising a facepiece, inhalation and exhalation check valves connected to said facepiece, a breathing bag adapted to fit around the neck of the wearer and to fit over his shoulders with sections falling over his chest and back, said bag being divided into two separate sections, one for inhalation and one for exhalation, breathing tubes connecting said facepiece with said breathing bag, a removable canister containing a carbon dioxide absorbing chemical disposed within the breathing bag between the inhalation and exhalation sections thereof, a clamp passing around a portion of the section of the'breathing bag enclosing said canister, a cylinder containing compressed oxygen, a control valve to regulate the fiow of oxygen, and an inflatable buoyancy vest attached to said breathing bag.

"I. Apparatus adapted for use underwater consisting of a self-contained breathing apparatus comprising a facepiece, directional flow check valves connected to said facepiece, breathing tubes, a breathing bag substantially oblong in shape provided with an opening in its central portion adapted to permit said bag to pass over the wearers head, an air purifying canister, the rear portion of said bag being split so as to form two overlapping sections adapted to hold said canister within the bag, said bag being divided in the front by a seam and in the rear by said canister into two separate sections, one for inhalation and one for exhalation, a clamp passing around said overlapping bag sections to hold said canister, a cylinder containing compressed oxygen carried on its side in a pocket in the front of the apparatus, a control valve to regulate the flow of oxygen from said cylinder, and an inflatable buoyancy vest attached to said breathing bag but containing an entirely separate volume reservoir, said vest being provided with means for controlling and varying its bouyancy.

8. Apparatus adapted for use underwater consisting of a breathing apparatus comprising a facepiece, inhalation and exhalation check valves connected to said facepiece, a breathing bag substantially oblong in shape provided with an opening in its central portion adapted to permit said bag to pass over a wearers head, an air purifying canister, the rear portion of said bag being split so as to form two overlapping sections adapted to hold said canister within said bag, said bag being divided in front by a seam and in the rear by said canister into two separate sections, one for inhalation and one for exhalation, a clamp passing around said overlapping bag sections to hold said canister, a cylinder containing compressed oxygen, an inflatable buoyancy vest attached to the breathing bag but containing an entirely separate volume reservoir, a double control valve to regulate the flow of oxygen from the cylinder, one side of the double valve regulating oxygen flow into the breathing bag and other side or said valve regulating oxygen flow into said vest, and valves disposed in the upper portion of the vest to permit the escape of gas therefrom when they are open.

OSCAR D. YARBROUGH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 926,671 Merryman June 29, 1909 1,814,506 Davis July 14, 1931 2,128,423 Manson Aug. 30, 1938 2,362,643 Lambertsen Nov. 14, 1944 2,402,984 Browne July 2, 1946 FOREIGN PATENTS Number Country Date 380,494 Italy May 16, 1940 

